Non-canting VCM-actuated autofocus

ABSTRACT

Techniques and apparatuses are described that enable non-canting VCM-actuated autofocus. These techniques and apparatuses enable multiple focal distances that are substantially free of imaging errors caused by canting of a lens housing. These multiple focal distances are provided by multiple positions of a lens housing relative to an image sensor. These positions can be free of cant through use of mechanical stops and corresponding mechanical stop-mates. By so doing, lower cost, faster focusing, higher image quality, lower power, or lower settling time can be achieved.

RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119(e) to U.S. patentapplication Ser. No. 15/175,318 filed on Jun. 7, 2016 which claimsbenefit of Provisional Application Ser. No. 62/181,516 filed Jun. 18,2015, the disclosure of which is incorporated by reference herein in itsentirety.

BACKGROUND

Currently, small and thin cameras have a collection of lenses that aremoved to and from an image sensor to focus on a particular scene. Tomake this movement of the lenses, many devices rely on voice-coil motors(VCMs), which use some form of mechanical spring along with anelectromagnet. The spring draws the lenses one direction and theelectromagnet, under control of the device, moves the lenses an oppositedirection. These lens elements are often placed within a barrel orcylindrical housing, which moves along a track within another structure.These current structures permit good imaging for cameras within small orthin devices.

These current devices, however, permit the housing to cant or tilt. Thiscanting, even at a very small angle, can reduce image quality,especially for array cameras. Array cameras have multiple image sensorsand lens collections to capture multiple images. Array cameras thencombine these multiple captured images to create a final resulting imagethat is of high quality. The quality of this resulting image, however,can be substantially reduced with even a very small amount of cant inany one of the lens collections.

The cant is often caused by the springs and the electromagnets not beingin perfect balance, for example, one spring being stronger than theother or one area of the electromagnet having a stronger force on it, orcaused by it, than another area. When this happens, two problems arise,a loss of focus on some area of the image sensor or an image capturethat is misaligned. The first problem affects even a camera with asingle image sensor, while both affect array cameras. Loss in imagequality for array cameras can also be due to the effect on the camera'sintrinsic matrix when different lens collections cant differently, whichadversely affects array camera calibration, causing the eventual fusedimage to be fused improperly.

This background description is provided for the purpose of generallypresenting the context of the disclosure. Unless otherwise indicatedherein, material described in this section is neither expressly norimpliedly admitted to be prior art to the present disclosure or theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Apparatuses of and techniques enabling non-canting VCM-actuatedautofocus are described with reference to the following drawings. Thesame numbers are used throughout the drawings to reference like featuresand components:

FIG. 1 illustrates cant of a lens housing.

FIG. 2 illustrates an example environment in which non-cantingVCM-actuated autofocus can be enabled.

FIG. 3 illustrates example image sensors of a camera system of FIG. 2.

FIG. 4 illustrates a two-position camera system having an image sensor,a lens stack, a lens housing, springs, electromagnets, mechanical stops,and mechanical stop-mates.

FIGS. 5-7 illustrate convex and concave mechanical stops and stop-mates.

FIG. 8 illustrates a planar-ring stop-mate having mechanical stop planesconfigured to contact mechanical stop-mates, which are also planar andconfigured as rings.

FIG. 9 illustrates a camera system having three focal positions.

FIG. 10 illustrates a camera system having three focal positions withmechanical stops and stop-mates that reduce movement of an image center.

FIG. 11 illustrates the computing device of FIG. 2 in greater detail.

FIG. 12 illustrates example methods for controlling a voice-coil motoreffective to autofocus without canting.

FIG. 13 illustrates various components of an electronic device that canimplement non-canting VCM-actuated autofocus in accordance with one ormore embodiments.

DETAILED DESCRIPTION

Voice-Coil Motors (VCMs) are a common and conventional mechanism toautofocus a camera, especially those with thin form factors present insmartphones and tablets. VCMs use a combination of springs andelectromagnetic force to adjust a position of a lens relative to animage sensor to focus on an object. VCMs suffer from an effect calleddynamic tilt, where the lens is not moved evenly through the focusrange. Instead, small mismatches in components cause the lens to tilt or“cant” at various positions of a lens relative to an image sensor. Thisis shown in exaggerated form in FIG. 1 with a cant angle 102 of a lenshousing 104 of a VCM-actuated camera. Note that even very small cantangles can negatively affect image quality, for example 0.1 to 1.0degree.

As discussed, the VCM uses a combination of springs and electromagneticforce to position the lens housing. The cant problem occurs due toimbalance between these components. During normal operation, the lens(via the lens housing) is positioned close to an image sensor formoderate to far object distances and moves away from the image sensorfor close distances, e.g., less than one meter. As the lens housing ismoved toward or away from the image sensor, the lens housing can cant ortilt, thereby reducing image quality.

In contrast, techniques and apparatuses are described below that enablenon-canting VCM-actuated autofocus. These techniques and apparatusesenable multiple focal distances that are substantially free of imagingerrors caused by the above-described canting of a lens housing or, at aminimum, are recurring and thus correctable. These multiple focaldistances are provided by multiple positions of a lens housing relativeto an image sensor. These positions can be free of cant through use ofmechanical stops and corresponding mechanical stop-mates. By so doing,lower cost, faster focusing, higher image quality, lower power, or lowersettling time can be achieved. For example, by using a mechanical stop,some positions require little power, low settling times, and lesssophisticated controllers due to the positions being set mechanicallyrather than through use of electromagnets. As noted, higher imagequality can also be attained due to reduction or elimination of tilt,which results in image center movement and out-of-focus imaging.

As described below, one-, two-, and three-position VCM cameras areshown, at least one of the positions of which is defined by mechanicalstops. These mechanical stops can be built into the structure of theVCM, for example on a lens housing, barrel through which the lenshousing moves, or surrounding structures.

These mechanical stops permit sufficient positions to enable ‘standard’and ‘macro’ mode imaging, e.g., imaging of objects that are about 20centimeters or less and those about 20 centimeters to infinity. With athird optional position, the range of focal imaging can be furtherexpanded, for example to 10-50 centimeters, 50 centimeters to 1.5meters, and 1.5 meters to infinity By so doing, cant that is normallyexhibited by VCMs can be eliminated or substantially reduced whileproviding positions necessary to cover a vast majority of imagingsituations.

The following discussion first describes an operating environment, thenexample cameras, a detailed description of an example computing devicehaving a camera, followed by techniques that may be employed in thisenvironment and device, and ends with an example electronic device.

Example Environment

FIG. 2 illustrates an example environment 200 in which non-cantingVCM-actuated autofocus can be embodied. Example environment 200 includesa computing device 202 having a camera system 204 capturing images of ascene 206. Camera system 204 includes an array of three image sensors208, each of which includes a lens stack 210.

Camera system 204 may include one, or be an array of, image sensors 208.When an array, image sensors 208 can be of similar or dissimilar types.Thus, the sensors can have different numbers of pixels, color-sensing ofpixels, sizes of pixels, or sensor size.

By way of example, consider FIG. 3, which illustrates image sensors 302of camera system 204. Image sensor 302-1 is monochrome with a clearcolor filter. This monochrome aspect improves signal-to-noise ratio inlow-light situations and can enable a high detail for a given pixelcount, or perform better in low-light environments due to an improvedsignal-to-noise ratio (SNR). Further, image sensor 302-1 may include afilter permitting infrared radiation to be sensed, which may not bedesired for color-pixel sensors because infrared radiation inhibitscolor fidelity, but does permit bandwidth captured by the imager to beexpanded into the Near Infrared (NIR). This can improve SNR in low-lightscenes, in some cases permitting image capture in near darkness. Imagesensors 302-2 and 302-3 have a lower pixel count using larger-pixelcolor sensors, which increases sensitivity, thereby enabling brighterimages with more vivid color.

As this one example shows, array cameras enable various advancements inthin (and non-thin) cameras but, as noted above, rely on post-processingof the images captured by each of the image sensors, in this case twolow-pixel-count color images with one high-pixel-count greyscale image,though this is provided as one non-limiting example for illustrationonly. Cant of the lens stack inhibits this post-processing, as imagecenter movement and focus errors prohibit the highest image quality.

With an example of an array camera explained, consider FIG. 4, whichillustrates a two-position camera system 402 having an image sensor 404,a lens stack 406, a lens housing 408, springs 410, electromagnets 412,mechanical stops 414, and mechanical stop-mates 416. This camera system402 is shown in cross-sectional view, while mechanical stops 414-1 and414-2 are shown in both cross section and plan views. Mechanical stop414-3 is not shown in cross section but is shown in plan view.

Image sensor 404 can be any of those described herein, for example oneof those illustrated in FIG. 3. Lens stack 406 includes one or morelenses used to project light from a scene and, if moved in a correctposition, focus light from the scene on to image sensor 404. Lenshousing 408 houses lenses of lens stack 406. The particular shape oflens housing 408 can be one of many different shapes and sizes, whetherin one or multiple parts. Here a cylindrical shape is implemented. Inmore detail, lens housing 408 includes a lens-retention section 418 andhere is shown including mechanical stop-mates 416 as part of a structureintegral with lens housing 408.

As noted in part above, mechanical stops 414 are configured to contactmechanical stop-mates 416 effective to prevent cant of the lens housing.This cant can be prevented such that the lenses are parallel with imagesensor 404. In some cases very slight angles exist but this small anglecan be accounted for during calibration of the camera system as itshould remain consistent. In this illustrated case a planar crosssection 420 of lens 422 is parallel to a plane 424 of image sensor 404for both positions in which mechanical stops 414 contact mechanicalstop-mates 416.

The mechanical stops (or sets of them) are both effective to preventcant of the lens housing, with one at a first position and the other ata second position, where each of the positions having different focaldistances to image sensor 404.

Springs 410 provide a spring force by which lens housing is pulled in adirection, which is often in opposition to a magnetic force ofelectromagnets 412. Electromagnets 412 provide a magnetic force whenprovided a current by a controller (e.g., in a device having camerasystem 402). Note that in this case an intermediate position is shownwhere neither of the mechanical stops are in contact with stop-mates.This is one alternative position described in greater detail below. Heretwo positions can be provided by the mechanical stops when lens housing408 contacts, through stop-mates 416, mechanical stops 414-1, 414-2, and414-3 or 414-4 and 414-5 (one or more other stops may also be includedwith stops 414-4 and 414-5, which are not shown). As shown, mechanicalstops 414-1, 414-2, and 414-3 include three projections arrangedeffective to define a stop plane that is parallel to planar crosssection 420 and plane 424 of image sensor 404.

In some cases, mechanical stops and stop-mates are configured to matesufficient to prevent cant as well as prevent non-cant movement (e.g.,side-to-side) of an image center of the scene on the image sensor. Thisis illustrated in FIGS. 5, 6, and 7.

FIG. 5 illustrates convex and concave stops and stop-mates. At oneposition, camera system 502 includes mechanical stops 504 that areconvex that mate to stop-mates 506 that are concave. At anotherposition, camera system 502 includes mechanical stops 508 that areconcave that mate to stop-mates 510 that are convex. As shown, theseconvex and the concave structures permit axial perpendicular movement512 of lens stack 406 and lens housing 408 relative to plane 424 ofimage sensor 404 while prohibiting, on full contact, axial parallelmovements 514 relative to plane 424 of image sensor 404.

FIG. 6 illustrates a camera system 602 having convex stop-mates 604 and606 and concave mechanical stops 608 and 610, though as part of adifferent configuration than FIG. 5. An optional middle position 612 andhigh and low positions 614 and 616, respectively, are shown in enlargedform for detail. At high position 614 (far focal position from imagesensor 404) convex stop-mates 604 contact concave mechanical stops 608.At a low position 616 (closest to image sensor 404), convex stop-mates606 contact concave mechanical stops 610. Note that in this example theconvex and concave structures are matching half spheres. When in fullcontact, both sets of mates and stops prevent movement parallel to theplane of image sensor 404, thereby prohibiting movement of an imagecenter of a captured scene (e.g., scene 206 of FIG. 2).

Camera system 602 includes mechanical stop-mates as part of a singlestructure, though each set of mates and stop-mates may be a singularstructure rather than all mates or stop-mates being one structure. Whilenot shown by this cross section of FIG. 6, the mates can be a singlering surrounding lens housing 408.

FIG. 7 illustrates a camera system 702 having convex stop-mates 704 and706 and concave mechanical stops 708 and 710. Like FIG. 6, middle, high,and low positions can be provided, though the middle position isoptional (none shown, see FIG. 6). Here, at a far focal position fromimage sensor 404, convex stop-mates 704 contact concave mechanical stops708. At a near focal position from image sensor 404, convex stop-mates706 contact concave mechanical stops 710. In this example, the convexand concave structures are narrow-to-wide and wide-to-narrow forming apoint or pyramid. When in full contact, both sets of mates and stopsprevent movement parallel to the plane of image sensor 404, therebyprohibiting movement of an image center of a captured scene (e.g., scene206 of FIG. 2). Like some other mates and stops described herein, thesecan be two stops and mates at opposing sides of lens housing 408, threeor more stops defining a plane, a consistent structure, for example, afull ring or plane, or three or more different stops and mates. FIG. 7illustrates one particular alternative in which two convex stop-matesand stops may be used for each of the high and low positions. Herepyramids of convex stop-mates 704 and 706, along with matching concavemechanical stops 708 and 710, allow alignment, reduce tilt, and preventparallel movement. This is shown with a top-down plan view illustratingtwo convex stop-mates 704.

FIG. 8 illustrates one such flat, consistent structure, where camerasystem 802 includes a planar-ring stop-mate 804 having mechanical stopplanes 806 and 808 that are configured to contact mechanical stop-mates810 and 812, respectively, which are also planar and configured asrings. Note the plan view showing mechanical stop plane 806 ofplanar-ring stop-mate 804 as well as their relationship to lens housing814.

While these examples illustrate various stops and stop-mates, others arealso envisioned, for example conic points or wave-cross-section ringsand mates. Many of these structure prohibit cant, movement of an imagecenter, as well as twist of a lens housing or lenses of a lens stack(twist can have negative effects in some applications of array cameras).

While each of the above camera systems are capable of more than twopositions, consider two specific examples of camera systems that havethree or more positions. FIG. 9 illustrates camera system 902 havingthree focal positions. A middle focal position 904 does not usemechanical stops and is an equilibrium position caused by springs 906.Middle focal position 904 includes a middle focal distance 908 from anearest lens of lenses 910 relative to image sensor 912.

FIG. 9 also illustrates a near focal position 914. Near focal position914 prohibits cant of lenses 910 and a lens housing 916 (shown in largerillustration) relative to a plane 918 of image sensor 912 using amechanical stop 920 and a mechanical stop-mate 922. As shown in one ofthe smaller illustrations, mechanical stop 920 is in contact withmechanical stop-mate 922, with each having two points shown in crosssection.

Far focal position 924 prohibits cant of lenses 910 within lens housing916 (shown in larger illustration) relative to plane 918 of image sensor912 using a mechanical stop 926 and a mechanical stop-mate 928. As shownin this smaller illustration, mechanical stop 926 is in contact withmechanical stop-mate 928, with each having two points shown in crosssection. Note that the various other forms of mechanical stops andstop-mates may also be used for camera system 902, for example thoseshown in FIGS. 5-8. By way of one example, FIG. 10 illustrates a camerasystem 1002 that may also provide three or more focal positions, in thiscase with mechanical stops and stop-mates that further aid to reducemovement of an image center. Note that the three focal distances 1004,1006, and 1008 in this example camera system are relatively similar.This is but one way in which some cameras, whether array cameras orotherwise, may operate.

Having generally described camera systems, mechanical stops, andmechanical stop-mates, this discussion now turns to FIG. 11, whichillustrates computing device 202 of FIG. 2 in greater detail.

Computing device 202 is illustrated with various non-limiting exampledevices: smartphone 202-1, laptop 202-2, television 202-3, desktop202-4, tablet 202-5, and video and still camera 202-6. Computing device202 includes processor(s) 1104 and computer-readable media 1106, whichincludes memory media 1108 and storage media 1110. Applications and/oran operating system (not shown) embodied as computer-readableinstructions on computer-readable media 1106 can be executed byprocessor(s) 1104 to provide some or all of the functionalitiesdescribed herein. Computer-readable media 1106 also includes imagemanager 1112. Image manager 1112 is configured to combine or processmultiple images of a same scene to provide a high-quality final image.Thus, image manager 1112 may create a composite image using multipleimages of the same scene, for example images captured by each of imagesensors 302 of FIG. 3. As noted above, computing device 202 includescamera system 204, which in turn includes lens stack 210 and imagesensor 404, as well as a focusing module 1114, which is configured tocontrol voice-coil motor 1116. Focusing module 1114 may be software orhardware or both (e.g., as an above-mentioned auto-focus system).

Focusing module 1114, as described below, is configured to controlmovement of lens stack 210 (generally via lens housing 408) throughcontrol of voice-coil motor 1116. This control is effective to cause oneor more focal position that are free or relatively free of cant and/ormovement of an image center.

In some cases, computing device 202 is in communication with, but maynot necessarily include, camera system 204 or elements thereof. Capturedimages are then received by computing device 202 from camera system 204via the one or more I/O ports 1118. I/O ports 1118 can include a varietyof ports, for example, by way of example and not limitation,high-definition multimedia (HDMI), digital video interface (DVI),display port, fiber-optic or light-based, audio ports (e.g., analog,optical, or digital), USB ports, serial advanced technology attachment(SATA) ports, peripheral component interconnect (PCI) express basedports or card slots, serial ports, parallel ports, or other legacyports. Computing device 202 may also include network interface(s) 1120for communicating data over wired, wireless, or optical networks. By wayof example and not limitation, network interface 1120 may communicatedata over a local-area-network (LAN), a wireless local-area-network(WLAN), a personal-area-network (PAN), a wide-area-network (WAN), anintranet, the Internet, a peer-to-peer network, point-to-point network,a mesh network, and the like.

Example Methods

The following discussion describes methods by which techniques areimplemented to enable use of non-canting VCM-actuated autofocus. Thesemethods can be implemented utilizing the previously describedenvironment and example camera systems, for example those shown in FIGS.2-11. Aspects of these example methods are illustrated in FIG. 12, whichare shown as operations performed by one or more entities. The orders inwhich operations of these methods are shown and/or described are notintended to be construed as a limitation, and any number or combinationof the described method operations can be combined in any order toimplement a method, or an alternate method.

FIG. 12 illustrates example methods 1200 for autofocusing a camerasystem. Note that these operations can be repeated or performedsimultaneously for a camera system having multiple image sensors, lensstacks, and so forth, e.g., those described in FIG. 3.

At 1202, distance data is received for a scene. In some cases this isdetermined using parallax of a stereo camera to compute depth and thusdistance to the scene. Distance data can be determined and received inmanners known, for example through radar, infrared, SONAR, and SODAR, toname but a few. Using FIG. 2 as an example, data can be receivedindicating a distance to some object in scene 206, e.g., a person 212.

At 1204, an autofocus focal position is determined based on the receiveddata distance. Assume, for illustration, that a user points the cameraof her smartphone toward a person on which the distance data is based.Focusing module 1114 then determines which focal distance is appropriateto focus that person on the image sensor or sensors of the camerasystem. Here we assume a three position camera system 902 as shown inFIG. 9.

At 1206, a force is applied by which to move a lens or lens stack tofocus the scene on an image sensor. This force can be an electromagneticforce, for example, using voice-coil motor 1116 to cause anelectromagnetic force to move from a middle focal position 904 to a highfocal position 924. Here focusing module 1114 controls voice-coil motor1116 to move lens stack 910. This force can balance another force, e.g.,a spring force, or can overcome a force until a mechanical stop is met.In this case, high focal position 924 is reached when mechanical stop926 meets mechanical stop-mate 928, whereby cant is reduced or removed.

The amount of force applied can be previously determined duringcalibration of the camera system. In some cases, however, a feedback isprovided when the mechanical stops and stop-mates meet, e.g., whencompletion of an electrical circuit or other electrical effect toindicate that a full contact with the stop and mate (or stops and matesif multiples).

Optionally, at 1208, an indication can be provided that the scene is infocus. This is sometimes simply showing the scene on a screen in focus,or some other indication that scene is in focus. At this point a usermay select to capture an image or images of the scene or not. If anarray camera, the images can be combined in some fashion to provide aresulting high quality image.

Returning briefly to FIG. 3, three images are capture of scene 206through image sensors 302-1, 302-2, and 302-3. These are then used tocreate a final image. Here image sensor 302-1 captures ahigh-resolution, monochromatic image of scene 206. Using the otherimages sensors 302-2 and 302-3, two more images, both color, arecaptured. These three are then combined to create a high quality image.As noted in part above, this combination is aided by these techniques asboth cant and movement of an image center are both reduced oreliminated. Note also that while the above example includes three imagesensors, two, four, or even many image sensors can be used. Also, withhigher numbers of images sensors, the techniques can further aid inenabling combination of these many images.

Example Electronic Device

FIG. 13 illustrates various components of an example electronic device1300 that can be implemented as a computing device and/or camera system,as described with reference to any of the previous FIGS. 2-12. Theelectronic device may be implemented as any one or combination of afixed or mobile device, in any form of a consumer, computer, portable,user, communication, phone, navigation, gaming, audio, camera,messaging, media playback, and/or other type of electronic device, forexample computing device 202 described with reference to FIGS. 2 and 11.

Electronic device 1300 includes communication transceivers 1302 thatenable wired and/or wireless communication of device data 1304, forexample, received data, transmitted data, or sensor data as describedabove. Example communication transceivers include NFC transceivers, WPANradios compliant with various IEEE 802.15 (Bluetooth™) standards, WLANradios compliant with any of the various IEEE 802.11 (WiFi™) standards,WWAN (3GPP-compliant) radios for cellular telephony, wirelessmetropolitan area network (WMAN) radios compliant with various IEEE802.16 (WiMAX™) standards, and wired local area network (LAN) Ethernettransceivers.

Electronic device 1300 may also include one or more data input ports1306 via which any type of data, media content, and/or inputs can bereceived, for example, user-selectable inputs, messages, music,television content, recorded video content, and any other type of audio,video, and/or image data received from any content and/or data source(e.g., other image devices or image sensors). Data input ports 1306 mayinclude USB ports, coaxial cable ports, and other serial or parallelconnectors (including internal connectors) for flash memory, DVDs, CDs,and the like. These data input ports may be used to couple theelectronic device to components (e.g., camera system 204), peripherals,or accessories for example, keyboards, microphones, cameras, andprinters.

Electronic device 1300 of this example includes processor system 1308(e.g., any of application processors, microprocessors,digital-signal-processors, controllers, and the like), or a processorand memory system (e.g., implemented in a SoC), which process (i.e.,execute) computer-executable instructions to control operation of thedevice. Processor system 1308 may be implemented as an applicationprocessor, embedded controller, microcontroller, and the like. Aprocessing system may be implemented at least partially in hardware,which can include components of an integrated circuit or on-chip system,digital-signal processor (DSP), application-specific integrated circuit(ASIC), field-programmable gate array (FPGA), a complex programmablelogic device (CPLD), and other implementations in silicon and/or otherhardware.

Alternatively or in addition, electronic device 1300 can be implementedwith any one or combination of software, hardware, firmware, or fixedlogic circuitry that is implemented in connection with processing andcontrol circuits, which are generally identified at 1310 (processing andcontrol 1310). Hardware-only devices in which non-canting VCM-actuatedautofocus may be embodied include those that convert, without computerprocessors, sensor data into voltage signals by which to controlfocusing systems (e.g., focusing module 1114).

Although not shown, electronic device 1300 can include a system bus,crossbar, or data transfer system that couples the various componentswithin the device. A system bus can include any one or combination ofdifferent bus structures, for example, a memory bus or memorycontroller, a peripheral bus, a universal serial bus, and/or a processoror local bus that utilizes any of a variety of bus architectures.

Electronic device 1300 also includes one or more memory devices 1312that enable data storage, examples of which include random access memory(RAM), non-volatile memory (e.g., read-only memory (ROM), flash memory,EPROM, EEPROM, etc.), or a disk storage device. Memory device(s) 1312provide data storage mechanisms to store the device data 1304, othertypes of information and/or data, and various device applications 1314(e.g., software applications). For example, operating system 1316 can bemaintained as software instructions within memory device 1312 andexecuted by processor system 1308. In some aspects, image manager 1112and/or focusing module 1114 is embodied in memory devices 1312 ofelectronic device 1300 as executable instructions or code. Althoughrepresented as a software implementation, image manager 1112 andfocusing module 1114 may be implemented as any form of a controlapplication, software application, signal-processing and control module,or hardware or firmware.

Electronic device 1300 also includes audio and/or video processingsystem 1318 that processes audio data and/or passes through the audioand video data to audio system 1320 and/or to display system 1322 (e.g.,a screen of a smart phone or camera). Audio system 1320 and/or displaysystem 1322 may include any devices that process, display, and/orotherwise render audio, video, display, and/or image data. Display dataand audio signals can be communicated to an audio component and/or to adisplay component via an RF (radio frequency) link, S-video link, HDMI(high-definition multimedia interface), composite video link, componentvideo link, DVI (digital video interface), analog audio connection, orother similar communication link, e.g., media data port 1324. In someimplementations, audio system 1320 and/or display system 1322 areexternal components to electronic device 1300. Alternatively oradditionally, display system 1322 can be an integrated component of theexample electronic device, for example, part of an integrated touchinterface. Electronic device 1300 includes, or has access to, a camerasystem, which includes lens stack 210 and image sensor 302 or 404 (notshown). Sensor data is received from camera system 204 and/or imagesensor 302 or 404 by image manager 1112, here shown stored in memorydevices 1312, which when executed by processor system 1308 constructs afinal image as noted above.

Although embodiments of non-canting VCM-actuated autofocus have beendescribed in language specific to features and/or methods, the subjectof the appended claims is not necessarily limited to the specificfeatures or methods described. Rather, the specific features and methodsare disclosed as example implementations of non-canting VCM-actuatedautofocus.

What is claimed is:
 1. A camera system comprising: an image sensor; anda lens housing having: a lens-retention section configured to retain oneor more lenses capable of focusing light from a scene onto the imagesensor; and a mechanical stop configured to contact a mechanicalstop-mate, the mechanical stop-mate including three or more projections,the three or more projections arranged effective to define a stop plane,the stop plane parallel to a planar cross section of at least one of thelenses, the planar cross section parallel to a plane of the imagesensor, the mechanical stop configured to contact the mechanicalstop-mate at the three or more projections effective to prevent cant ofthe lens housing.
 2. The camera system as recited in claim 1, furthercomprising a second mechanical stop, the first-mentioned mechanical stopand the second mechanical stop both effective to prevent cant of thelens housing, the first-mentioned mechanical stop at a first positionand the second mechanical stop at a second position, the first andsecond positions having different focal distances to the image sensor.3. The camera system as recited in claim 1, wherein the mechanicalstop-mate comprises a ring surrounding the lens housing, the ringconfigured to contact the mechanical stop with the three or moreprojections when in a first position and further configured to contact asecond mechanical stop with three or more other projections when in asecond position, the first and second positions having different focaldistance to the image sensor.
 4. The camera system as recited in claim1, wherein the mechanical stop and the mechanical stop-mate areconfigured to mate sufficient to prevent the cant and to further preventnon-cant movement of an image center of the scene on the image sensor.5. The camera system as recited in claim 4, wherein the mechanical stopincludes three or more concave structures corresponding to the three ormore projections of the mechanical stop-mate, the projections and theconcave structures permitting axial perpendicular movement relative tothe plane of the image sensor while prohibiting, on full contact, axialparallel movement relative to the plane of the image sensor.
 6. Thecamera system as recited in claim 5, wherein the projections and concavestructures are matching conic, pyramid, or narrow-to-wide structures. 7.The camera system as recited in claim 1, further comprising a secondimage sensor, a second lens housing having a second lens-retentionsection configured to retain one or more other lenses capable offocusing light from the scene onto the second image sensor and a secondmechanical stop-mate configured to contact a second mechanical stop, thesecond mechanical stop configured to contact the second mechanicalstop-mate effective to prevent cant of the second lens housing relativeto a second planar cross section of at least one of the second lenses,the second planar cross section parallel to a second plane of the secondimage sensor.
 8. The camera system as recited in claim 7, furthercomprising an image manager configured to receive first and secondimages from the first and second image sensors, respectively, andcombine or process the first and second image sensors to create acomposite image of the scene.
 9. An array camera system comprising: afirst image sensor; a first lens housing having a first lens-retentionsection configured to retain one or more first lenses capable offocusing light from a scene onto the first image sensor and a firstmechanical stop-mate configured to contact a first mechanical stop; thefirst mechanical stop, the first mechanical stop configured to contactthe first mechanical stop-mate effective to prevent cant of the firstlens housing relative to a first planar cross section of at least one ofthe first lenses, the first planar cross section parallel to a plane ofthe first image sensor; a second image sensor; a second lens housinghaving a second lens-retention section configured to retain one or moresecond lenses capable of focusing light from the scene onto the secondimage sensor and a second mechanical stop-mate configured to contact asecond mechanical stop; and the second mechanical stop, the secondmechanical stop configured to contact the second mechanical stop-mateeffective to prevent cant of the second lens housing relative to asecond planar cross section of at least one of the second lenses, thesecond planar cross section parallel to a plane of the second imagesensor.
 10. The array camera system as recited in claim 9, wherein thefirst or second mechanical stop includes three or more projections, thethree or more projections arranged effective to define a stop plane, thestop plane parallel to the first or second planar cross section and theplane of the first or second image sensor, respectively.
 11. The arraycamera system as recited in claim 9, wherein the first or secondmechanical stop includes a flat structure defining a stop plane, thestop plane parallel to the first or second planar cross section and thefirst or second plane of the first or second image sensor, respectively.12. The array camera system as recited in claim 9, wherein the first orsecond mechanical stop-mate comprises a ring surrounding the first orsecond lens housing, the ring configured to contact the first or secondmechanical stop when in a first position and a third mechanical stopwith in a second position, the first and second positions havingdifferent focal distance to the first or second image sensor,respectively.
 13. The array camera system as recited in claim 9, whereinthe first or second mechanical stop and the first or second mechanicalstop-mate are configured to mate sufficient to prevent the cant and tofurther prevent non-cant movement of an image center of the scene on thefirst or second image sensor, respectively.
 14. The array camera systemas recited in claim 13, wherein the first or second mechanical stopincludes a convex or concave structure and the first or secondmechanical stop-mate includes the other of the convex or concavestructure, the convex and the concave structures permitting axialperpendicular movement relative to the plane of the first or secondimage sensor while prohibiting, on full contact, axial parallel movementrelative to the plane of the first or second image sensor, respectively.15. The array camera system as recited in claim 14, wherein the convexand concave structures are matching conic, pyramid, or narrow-to-widestructures.
 16. A camera system configured to provide three focalpositions, the camera system comprising: a first focal positionprohibiting cant of lenses within a lens housing relative to a plane ofan image sensor using a mechanical stop and a first mechanicalstop-mate, the mechanical stop configured to mate with the firstmechanical stop-mate effective to prevent non-cant movement of an imagecenter of a scene on the image sensor and to prevent cant of the lenshousing relative to a planar cross section of at least one of thelenses, the planar cross section parallel to a plane of the imagesensor; a second focal position prohibiting cant of the lenses withinthe lens housing relative to the plane of the image sensor using themechanical stop and a second mechanical stop-mate; and a third focalposition between the first and second focal position, the third focalposition enabling focus of a scene on the image sensor at focaldistances less that the first position and greater than the secondposition.
 17. The camera system as recited in claim 16, furthercomprising: springs having a spring force by which the first position orthe second position is provided; and electromagnets having a magneticforce when provided a current by which another of the first position orthe second position is provided.
 18. The camera system as recited inclaim 16, wherein the mechanical stop comprises a ring surrounding thelens housing.
 19. The camera system as recited in claim 16, furthercomprising a focusing module configured to provide a force by which toprovide the first or second position.
 20. The camera system as recitedin claim 19, wherein the focusing module powers an electromagneteffective to balance a spring force of a mechanical spring or springs atthe first or second position, the balancing providing the thirdposition.